how to add a labelling under the r plots code example

Example: label points in plot in r

# Example of labeling points
attach(mtcars)
plot(wt, mpg, main="Milage vs. Car Weight",
   xlab="Weight", ylab="Mileage", pch=18, col="blue")
text(wt, mpg, row.names(mtcars), cex=0.6, pos=4, col="red")